PHP-Menampilkan Jumlah Pengunjung

index.php

<?php
session_start();
mysql_connect("localhost","root","");
mysql_select_db("dbPengunjung");
if(!isset($_SESSION['okay']))
{
$_SESSION['okay']=session_id();
mysql_query("update pendatang set jumlah = jumlah + 1");
}
$data = mysql_query("select * from pendatang ");
$tampil = mysql_fetch_array($data);
$a = $tampil[0];
echo "<h1>Anda pengunjung Ke ".$a;
?>